Spray injection nozzle



Aug. 6; 1940. I w, B AL 22 10,733

' SPRAY INJECTION NOZZLE Filed Nov. 27, 1937 2 Sheets-Sheet 1 H WAR R T. TABS l] EVERETT M. PURDY ,fl BY THEIR ATTORNEYS w. T. TABB El AL SPRAY INJECTION NOZZLE Aug. 6, 1940.

Filed Nov. 27, 1937 2 Sheets-Sheet 2 INVE NTOR5 WARNER T. TABB EVERETT M. PURDY BY THEIR ATTORNEYS Patented Aug. 6, 1940 UNITED STATES PATENT OFFICE SPRAY INJECTION NOZZLE Application November 27. 1937, Serial No. 176,897

4 Claims.

This invention relates to spray injection nozzles for internal combustion engines of the Diesel type and it is an object of this invention to provide an improved nozzle of the type described which will provide jets of fuel having desired characteristics and which is of such construction that nozzles having diiferent characteristics may be readily constructed. A further object of this invention is to provide a stem for the valve controlling the discharge from the spray nozzle which will cooperate with the nozzle tip in determining the fuel jet characteristics. It is also an object of this invention to provide a suitable spring means for determining the fuel pressures at which movements of the valve stem occur and for determining the nature and degree of such movement. I

In the drawings:

Figure l is a view partly in longitudinal section and partly in elevation of a spray injection nozzle in accordance with this invention assembled with the holder by which it is secured to the engine cylinder.

Fig. 2 is a partial longitudinal sectional view, drawn to a larger scale, of one form of a spray injection nozzle in accordance with this invention, the valve stem being shown partly in elevation and partly in section through one of the grooves for the passage o f the fuel;

Fig. 3 is a fragmentary sectional" view drawn to a still larger scale and showing the relation of the nozzle tip and the discharge grooves in the nozzle stem;

Figs. 4 and 5 Y are sectional views similar to Figs. 2 and 3 of a nozzle of modified construction;

.Fig. 6 is a fragmentary view in end elevation showing a portion of the nozzle stem of either Fig. 2 or Fig. 4 at one of the grooves of the stem;

Figs. '7, 8, 9 and 10 are fragmentary sectional views showing the relation of the grooves in the stem to the nozzle tip in nozzles of modified construction, the stems being partly in section and partly in elevation;

Figs. 11 and 12 are fragmentary sectional views similar to Figs. 7 to 10 of a further modification,

the views being taken substantially at right angles; and

Fig. 13 is a partial transverse sectional -view, taken as on line l3-l3 of Fig. 10.

As shown in the drawings, a spray injection nozzle constructed in accordance with this invention comprises a holder portion I, a tip portion 2 having a portion of reduced diameter and forming a shoulder, as at 2, to be engaged by the flange 3 of a sleeve 01' collar 3 arranged to be threaded on an end of the holder portion l to secure the holder and tip portions together. The holder I is threaded at its central portion to engage the wall of the engine cylinder at its other end for the attachment of a pipe (not shown) through which fuel is supplied. The fuel passes through a centrally located passage or bore I' in the holder to a chamber 4 formed by recesses in the abutting ends of the holder l and tip 2. A centrally located passage or bore 2*, larger in diameter than the bore "l extends from the chamber 4 tothe outer end of the nozzle tip 2. Mounted in the bore 2 and' extending into the chamber 4 is a valve stem 6 threaded at its upper end .to receive a nut 8 which is shouldered,

as at 8, to bear upon the inner edge of a primary spring i0, and as at 8 to bear upon a plate ll carried on the inner edge of a secondary spring I2 mounted in the portion of chamber 4 formed in the tip 2.

The primary spring 10 comprises a plurality of initially cupped spring disks having a central opening to receive the valve stem 6 and of less diameter than the opening in the tip 2 in which they are mounted. The spring I0 is supported at its outer edge upon a spring wire ring I4 and in I, the space between the spring Ill and the wall of the chamber 4 is placed a filler ring l5 upon which rests a spring wire ring l6 which supports the outer edge of the secondary spring l2. The secondary spring l2 comprises a plurality of initially cupped spring disks having a central opening to permit passage of the nut 8 which bears on the primary spring l0. The plate II is of annular shape and gradually reduces in thickness from its inner edge so as to normally bear on the secondary spring I2 only at its inner edge. At its outer'edge the plate II has a narrow band portion of uniform thickness forming a pad or abutment adapted to engage an annular shim I! of suitable thickness mounted on the outer edge of the spring l2 to limit the movement of the plate II. The recess in the outer end of the holder 1 is of less diameter than the plate ll so the outer end of the holder l forms a shoulder which engages the plate H and holds the plate in such position when the parts are assembled as to place the secondary spring under an initial compression.

The nut 8 is threaded on the valve stem 6 to engage the primary spring l0 and place the spring Ill under an initial compression which serves to hold a valve face l8 on the valve stem 6 in engagement with a cooperating valve seat formed in the bore 2*, the adjustment of the nut 8 determining the initial pressure of the spring i0 and the fuel pressure necessary to operate the valve stem 3 to permit fuel discharge to the engine cylinder. A pin 9 holds the nut in adjusted position. The valve stem-6 is formed with guiding portions 6 and 6 of substantially the diameter of the bore 2", the guiding portion 3 being of slightly greater diameter than the portion 3' to fit a correspondingly enlarged portion of the bore 2*. The portion 6 of the valve stem extends from adjacent the valve surface l3 to the outer end of the valve stem while a portion of the valve stem of reduced diameter intervenes between the valve surface I 8 and the portion 6'. The nut 8 is slotted longitudinally and transversely to permit the flow of fuel from the chamher 4 past the plate II and springs I2 and ill to the bore 2 in the tip 2 and the portion 6 of the valve stem 8 are grooved, as at 20, to permit the fuel to fiow to the annular space about the reduced portion of the valve stem adjacent the valve seat I9. The portion 8 of the valve stem 3 is provided with a plurality of grooves 2| uniformly spaced about the valve stem to permit the discharge of fuel upon the movement of the valve surface it! from its seat I8. The grooves 2| are substantially rectangular in cross section and have a portion 2| of uniform depth extending for a considerable part of the length of the portion 6 of the valve stem, then the depth of the groove gradually increases and then decreases along the arc of a circle, as at 2|, after which it is of uniform depth for a short distance, as at 2|, the depth at 2| less than at 2 i and then the depth gradually increases along the arc of a circle, the arc being reversed with respect to the are at 2|.

In the operation of the device described, fuel under pressure is supplied from the pump (not shown) through the passage l and the fluid pressure is built up in the chamber 4 and bore 2 until the unbalanced pressure acting on the valve stem 6 is sufficient to overcome the resistance of the spring in and shift the valve stem 5 and nut 8 until the nut 8 engages the plate H. The movement of the valve stem 3 separates the valve surface |8 from the valve seat l9 and permits fuel to flow from the chamber 4 through the grooves in the nut 8 and valve stem 8 past the valve surface I8 and through the grooves 2| to discharge.

As the spring I2 is held under an initial pressure by the plate movement of the valve stem 6 and nut 8 is stopped when the nut 8 engages the plate I I and further movement does not take place until the fuel pressure is built up sufficiently for the unbalanced pressure on the valve stem 3 to overcome the resistances of both springs Ill and I2. Upon overcoming the resistances of springs l0 and I2 the valve stem 6 and nut 3 are moved, carryingwith them the plate until the plate engages the shim H on the spring l2 whereupon further outward movement of the valve stem 6 and nut I is prevented.

The valve stem 6 projects beyond the end of the tip 2 and the inwardly curved bottoms of the portions 2| of the grooves 2| cause the fuel jets, discharged from the grooves 2|, to be directed inwardly toward a common point on the axis of the valve stem 3 spaced outwardly from the end of the valve stem, the curvature of the bottoms of the groove portions 2| determining the distance of such point outwardly from the end of I valve seat I! and the groove portions 2| are of such length that their inner ends have not passed the outer end of the tip 2 when the movement of the valve stem 3 is stopped by the engage ment'of the nut 3 with the plate I I. Upon movement of the valve stem 3 with both springs l0 and I2 the end of the uniform shallow portion 2| passes the end of the tip 2 and the portion of gradually increasing depth of groove portion 2|" starts to move out past the end of the tip 2 giving discharge openings to the grooves of gradually increasing capacity and which have the groove bottoms curved so as to direct the jets outwardly or away from the axis of thevalve stem. That is, during the movement of the valve stem against the action of spring ||I only the jets are directed inwardly and increase in volume up to the capacity of the shallow portions 2| of the grooves and thereafter remain of constant volume until spring I2 is also overcome. When spring I2 is also overcome the jets gradually increase in volume and are directed outwardly for the remainder of the outward movement of the valve stem 3.

In the modification shown in Figs. 4 and 5 there is provided the holder I having the central passage I leading to a recess forming part of a chamber 4 and a tip 2 secured to the holder by the collar or sleeve 3 and having a bore 2 which extendsto the recess in the tip 2 which cooperates with the recess in the holder I in forming the chamber 4. In the chamber 4 is the spring 33 consisting of a plurality of annular spring disks supported at their outer edge upon a spring wire ring 3| and at their inner edge supporting a spring wire ring 32 positioned so as to be engaged by a shoulder on a nut 33 secured by a pin 34 in adjusted position on the threaded upper end of a valve stem 33. The spring disks are cupped when in a free state and the nut 33 is adjusted on the valve stem 33 to place the spring 33 under an initial pressure and thus determine the fuel pressure at which the valve stem 33 will be operated against the action of the spring 34 to shift the valve surface 33 on the valve stem 33 from the valve seat 31 in the bore 2 and permit the discharge of fuel from the nozzle. To aid in adjusting the spring pressure to the desired degree shims 33 may be placed between the spring wire 32 and the nut 33 and shims 33 may be placed between the spring wire 3i and the bottom of the recess in the tip 2. i

As in the previous modification the valve stem 35 is provided with a guiding portion 33* which fits the bore 2 and is slotted as at 40 to permit the passage of fuel and with a guiding portion 35" of slightly larger diameter which fits a correspondingly enlarged portion of the bore 2 and which is provided with a plurality of grooves 4| of rectangular cross-section. Each groove 4| comprises a portion 4 I of uniform depth extending outwardly from adjacent the valve surface 33 and which merges into a shorter portion 4| of uniform but less depth than the groove portion v 4| and a groove portion 4| of gradually increasing depth which extends from the groove portion 4| to the end of the valve stem, the groove bottoms of the groove portions 4| being curved so as -to direct the jets inwardly to a point on the axis of the valve stem as in the previous modification.

Inthis modification, increase of the fuel pressure to the point at which the resistance of the spring 30 is overcome causes the valve stem 33 and nut 33 to move until further movement is prevented by the engagement of the nut I with the shims '39, that is, the outward movement of the valve stem is completed in the one operation. This outward movement of the valve stem separates the valve surface 36 from the valve seat 31 and permits the fuel to flowfrom the chamber 4 through the grooves 2 and bore 2 in the tip,

grooves 40 in the valve stem, past the valve surface 38 and through the grooves 4| in the valve stem portion 35 to be discharged as jets convolume of fuel discharged increases gradually, as

thevalve stem moves outwardly, up to the capacity of the shallow groove portions 4| and thereafter remains constant for the remainder'of the movement of the valve stem 35.

In Fig. 7 only the outer ends of a nozzle tip 2 and a valve stem are shown, the valve stem being mounted in a .bore 2' in the tip and having a portion 45 of slightly greater diameter than the remainder of the valve stem snugly fitting a correspondingly enlarged end portion of the bore 2". The valve stem 45 is provided with a valve surface 46 which cooperates with a valve seat 41 in controlling the passage of fuel and the valve stem portion 45 has a plurality of grooves 5| of rectangular cross-section for the greater portion of their length and which extend from adjacent the valve surface 48 to the outer end of the valve stem. Each groove 5i comprises a groove portion 5| of substantially uniform depth which merges with a shorter groove'portion 5| of uniform but less depth than the groove portion Iil and adjacent the junction of the groove portions 5! and 5| is a recess shown formed as a cylindrical bore of greater width and depth than the groove portion 5|. Extending from the shallow groove portion 5l to the end of the valve stem is a groove portion 5| of gradually increasing depth, the bottom of the groove portion 5| curving gradually inwardly so as to direct each iuel jet inwardly causing the fuel Jets to converge at a point a short distance from the outer end of the valve stem. The valve stem of Fig. '7 is suitable for operation with a spring ar-' rangement such as is shown in Fig. 2 which, on the yielding of the first or primary spring, would give a movement of the valve stem 45 which would separate the valve surface 45 from the valve seat 41 permitting a flow of fuel therebetween and which would'leave the inner ends of the shallow groove portions 5| slightly within the bore 2 so as to produce a plurality of inwardly converging jets, the volume of which is governed by the capacity of the shallow groove portions 5P. Further movement of the valve stem 45 upon the yielding of the secondary spring would bring the bores 5| beyond the outer end of the tip 2 giving a plurality of jets directed outwardly away from the axis of the valve stem 45 and of gradually increasing volume as more of the bores 51 of the grooves are exposed beyond the end of the tip 2. The yielding of the secondary spring, however, would be limited so as to expose less than half of the cross-sectional jets delivered by such grooves to converge. the

. bottoms of the outer end portions of the grooves need not be so curved but may be flat and disrected inwardly as shown in Fig. 8 and'the jets will be directed inwardly to converge at a point on the axis of the valve stem a short-distance outwardly from the end of the valve stem. Thus in Fig. 8 the valve stem 55 is shown with grooves of rectangular cross-section ll extending substantially from the valve surface 55 to the outer end of the valve stem, each groove'comprising a portion of uniform depth, a portion li having a curved bottom and of'varying depth, a portion 5l of uniform but less depth than the groove portion ii and a portion Ol which gradually increases in depth towards the outer end of the valve'stem and the bottom of which is flat and directed inwardly so as to cause the fuel jets to converge as in the previous modifications. This modification when associated with a spring arrangement as shown inFig. 2 would also give a plurality of jets converging at a point on the axis of the valve stem and of a volume determined by the capacity of the shallow groove portions 8l when the valve surface 56 is separated from the valve surface 51 upon the yielding of the primary spring and the jets would diverge and be of gradually increasing volume as the yielding of the secondary spring permitted movement of the valve stem to shift the outer ends of the groove portions ll past the end of the tip 2.

In the modifications described above the valve stem has been of sufficient length to project beyond the outer end of the nozzle tip but the invention is not limited to such a construction as the tip may be made of sufl icient length to extend beyond the outer end of the valve stem at all times. Thus in Fig. 9 a tip 2' is shown associated with the valve stem 35 of Figs. 4 and 5, the tip 2' being of such length that it always ex tends beyond the valve stem 35. This arrangement of valve stem and nozzle tip could be as-. sociated with the spring arrangement of either Fig. 2 or Fig. 4 and in both cases the fuel jets, upon the separation of valve surface 36 from valve seat 31, would be determined by the capacity of the shallow groove portions 44* and as the. end of the valve stem never projects beyond the end of the tip 2' the fuel jets tend to follow the surface of the bore 2 and to diverge upon passing beyond the tip 27 as well as to follow the bottom of the grooves.

The grooves in the enlarged end portions of the valve stems of the previous modifications have been shown and described as being of rectangular cross-section but they may be of other shapes, as triangular, as shown in Figs. 10 and 13. In this modification the grooves II in the valve stem 85 are triangular in shape, the groove portion 1i which extends from adjacent the valve surface 66. being of uniform depth and width for the major portion of its length and then tapers, both in width and depth, to merge with the shallower groove portion II which is of uniform width and depth for a short distance and then opens into theend groove portion 1l which widens and deepens continuously to the end of the valve stem. This modification when associated with a spring arrangement, as in Fig. 2, gives a plurality of jets which at first converge and are of a volume determined by the shallow groove portion II and then diverge and gradually increase in volume as the ends of the groove portions II are moved past the end of the tip 2.

Each of the previous modifications has been shown and described as having the outer end portion of the valve stem provided with a plurality of grooves, all the grooves in each modification being of identical construction causing the fuel jets of each modification to be of uniform volume and direction but the grooves may be of I varied construction as shown in Figs. 11 and 12 in which there is shown a valve stem 16 in the bore 2 of a tip 2 which is provided with a plurality of pairs of grooves of different construction, the grooves of each pair being placed diametrically opposite on the valve stem and the pairs. being arranged to distribute the grooves uniformly about the valve stem. The grooves shown in Figs. 11 and 12 comprise a pair of grooves, such as groove M of Fig, 2, and a pair of grooves Bl of somewhat similar construction but having shallower portions 8| of greater length than the shallow portions 2 l of the grooves 2| though of the same uniform depth. The other groove portions 81 Bi and Ol correspond to the groove portions 2!, 2| and li respectively, except that groove portion iii is slightly shorter than groove portion 24 The grooves 2| provide jets as described in connection with Fig. 2, that is, the jets converge and are of a volume determined by the capacity of the shallow groove portions 2 I during the first part of the movement of the valve stem Hi and diverging and of gradually increasing volume during the latter part of the movement of the valve stem. The length of the shallow portions 8| of the grooves 8|, however, are of such length that their inner ends are always within the bore 2* of the tip 2 so that the jets from the grooves 8| always converge and never exceed the volume determined by the capacity of the shallow groove portions 8l. Thus during the first part of the outward movement of the valve stem all of the jets converge and dur-, ing the latter part of the valve stem movement two of the jets converge and two diverge.

While it is preferred to use the spring arrangement of Fig. 2 with valve stems having some of the groove constructions described and to use the spring arrangement of Fig. 4 with valve stems; having others of the spring constructions shown, it is t be understood that either spring arrangement may be used upon provision being made for providing the desired amount of movement of the valve stem for each groove construction.

What is'claimed is:

1. In a fuel nozzle, a nozzle .tip having a fuel discharge opening, a stem movably mounted in said opening, said stem having grooves arranged to discharge fuel in one direction in one position of said stem and in another direction in another position of said stem, and means for operating said stem to both positions.

2. In a fuel nozzle, a nozzle tip having a fuel discharge opening, a stem movably mounted in said opening, said stem having grooves arranged to dischargefuelin different directions in different positions of said stem and spring means opposing predetermined pressures to movement of said stem to said different positions.

3. In a fuel nozzle, a nozzle tip having a fuel discharge opening, a stem movably mounted in said opening, said stem having grooves arranged to discharge fuel in one direction in one position of the stem and in another direction in a second position of the stem, a spring means under initial stress opposing movement of said stem to the first position and a second spring means under initial stress opposing movement of saidstem from the first to the second position.

4. In a fuel nozzle, a nozzle tip having a fuel discharge opening, a stem movably mounted in said opening, said stern having grooves arranged to discharge fuel in a converging direction in one position of said stem and in a diverging direction in a second position of said stem, a spring means under initial stress opposing movement of said stem to said first position and a second spring means under initial stress opposing movement of said stem to the second position.

WARNER T. TABB. EVERETT M. PURDY. 

